1. Field of the Invention
This invention relates to absorbent articles such as sanitary napkins, pantyliners, incontinent products or the like and, more particularly, relates to an individually wrapped absorbent article in which the article is releasably secured to a peel strip and folded and sealed to form a package. The package is then wrapped and folded to form a pouch for storing and transporting the absorbent article. The invention additionally relates to a method of wrapping and folding an individually wrapped absorbent article of the aforementioned type and to an apparatus for practicing the method.
2. Discussion of the Related Art
Absorbent articles are well known for absorbing and retaining bodily fluids such as urine, menstrual fluids, blood, etc. Typical of these absorbent articles are sanitary napkins, pantyliners, incontinent products, and the like. The problems addressed by the art will be discussed primarily with reference to sanitary napkins, it being understood that pantyliners, incontinent products, and other absorbent articles also exhibit some or all of these problems.
The two types of sanitary napkins currently in use are a wingless or tabless type that is generally rectangular in shape and a winged or tabbed type that has wings or tabs (hereinafter "wings") extending laterally beyond the lateral edges of the main body of the napkin in a longitudinally central portion thereof. The typical sanitary napkin of either type comprises an absorbent core encased or enclosed within an envelope or sheath that includes a topsheet, also referred to as a "cover," and a backsheet, also referred to as a "baffle." The topsheet is designed to face the user and is liquid-permeable to permit liquid passage to the absorbent core where the liquid is retained. The backsheet is liquid-impermeable. A strip of garment-attachable adhesive is secured on the outer surface of the backsheet to permit releasable or detachable securement of the napkin to a user's undergarment. In the case of a winged or tabbed type napkin, additional adhesive strips or patches are secured to the bottom surface of the wings to permit securement of these wings to the user's undergarment. The adhesive strips can be transferred to the napkins by applying the adhesive to the releasable peel strips, and the adhesive is then transferred to the napkins when the peel strip is attached to the backsheet or baffle. The peel strip protects the adhesive from contamination until the napkins are ready for use, at which time the user removes the peel strips.
Individually wrapped sanitary napkins are desirable for a variety of reasons. For instance, they are compact (e.g., they can be conveniently carried in a consumer's pocket or purse), they prevent the sanitary napkins and the liners from becoming contaminated or soiled prior to use, and used napkins can be disposed of using the pouches or other wrapping materials. Individually wrapped sanitary napkins are disclosed, for example, in U.S. Pat. No. 3,973,567 to Srinivasan et al. (the Srinivasan patent); U.S. Pat. No. 4,556,146 to Swanson et al. (the Swanson patent); and U.S. Pat. No. 5,413,568 to Roach et al. (the Roach patent). All of these patents disclose a sanitary napkin having a backsheet portion adhered to a liner or peel strip that also forms at least part of a wrapper for the napkin. The Srinivasan and Swanson patents disclose individually wrapped wingless or tabless disposable sanitary napkins, whereas the Roach patent discloses an individually wrapped winged or tabbed sanitary napkin.
Conventional individually wrapped sanitary napkins such as those disclosed in the Srinivasan, Swanson, and Roach patents exhibit several drawbacks and disadvantages. For instance, they are relatively difficult to open. In the case of the Swanson patent, the wrapper faces and receives the backsheet portion of the napkin so as to present longitudinal and lateral flaps surrounding the napkin. The napkin and affixed wrapper are then tri-folded as a unit. The lateral edges of the longitudinal flaps are frangibly sealed along their entire length to prevent napkin contamination. These seals must be broken when unwrapping the assembly. This seal breaking requirement hinders unwrapping. In addition, the wrapper is ill-suited for disposal of a used napkin because it is not substantially larger than the napkin.
Napkins of the tabbed or winged type also exhibit additional wrapping challenges. For instance, in the Roach patent, a tabbed or winged type napkin is disclosed which has a backsheet that is releasably adhered to a wrapper similar to the manner in which the Swanson's backsheet is adhered to the corresponding wrapper. However, the ends of the wings extend beyond the lateral edges of the wrapper. The exposed wings are folded longitudinally over the topsheet of the body of the napkin so that the wings are aligned and adjacent to the topsheet of the napkin with their ends facing the longitudinal centerline of the napkin and with their adhesive patches or strips facing upwardly. The wings must be covered with at least one and possibly two separate or dedicated pieces of release liner to protect the adhesive patches on the wings. The additional release liner(s) must be individually removed by the consumer prior to napkin use. This extra step is inconvenient at best and also presents the consumer with at least one additional piece of waste material for disposal. Moreover, because the wrapper is not substantially wider than the body of the napkin, it is rather difficult for the consumer to use the wrapper to dispose of a used napkin.
Another problem associated with conventional individually wrapped sanitary napkins is that production is hindered because wrapping and folding requires a separate process and apparatus and/or because the wrapping and folding operations cannot be performed in-line. Wrapping and folding instead are performed via rather large and complex drum, roll, and striker blade configurations that require at least one and usually several changes in the direction of napkin conveyance during the wrapping and folding processes. Examples of typical processes exhibiting these disadvantages can be found in U.S. Pat. No. 3,635,462 to Joa; U.S. Pat. No. 4,701,156 to Larsonneur; and U.S. Pat. No. 5,176,615 to Munsch.